A near-pristine system of seven watercourses within the Christmas Island National Park, including permanent and intermittent streams and most of the surface water on the island. It is the first Australian Ramsar Site to include surface and subterranean karst features. The sites numerous wetland types support important populations of endemic and/or threatened species including Christmas Island Hawk-owl Ninox natalis and Brown Goshawk Accipiter fasciatus natalis, Abbotts Booby Papasula abbotti, the gecko Lepidodactylus listeri, and the Blind Snake Ramphotyphlops exocoeti. The site plays host to the annual mass migration and spawning of red crabs (Gecarcoiodea natalis) and provides critical habitat for the blue crab (Discoplax hirtipes). In total, 20 species of land crabs are found within the site, all migrating to the ocean to spawn. The Dales are a popular sightseeing destination for local people and tourists and one of them has religious significance for Buddhist inhabitants of Chinese background. The principal threat to the site comes from introduced species, particularly the Yellow Crazy Ant Anoplolepis gracilipes, which was accidentally introduced in the first half of the 20th century and whose supercolonies proliferated markedly in the mid- to late 1990s.